The greatest single sacrifice in American blood and treasure this country has ever known is over, ending four score and seven years to the day after the nation was born with a declaration of life, liberty and the pursuit of happiness.

Gen. Robert E. Lee’s Confederate Army of Northern Virginia is now in retreat.

For brothers-in-arms fighting against each other in a war between states, often pitting actual brothers, cousins, fathers and uncles on opposite sides, it could be said that this most terrible battle in this most uncivil of wars will go down in history as the worst scene of fratricide ever committed in modern warfare.

Of the 160,000 troops who poured into battle over the past three days, nearly one in three has been wounded, captured or killed, or is missing.

It will take days to count and bury the dead now strewn across the rolling farmlands, forests and rocky knolls that became the battlefield of Gettysburg, but officials expect those killed in action to number nearly 8,000, with another 27,000 wounded between the two sides. At least another 10,000 are also now captured or missing.

The survivors of both bruised and battered armies spent most of today in exhausted shock, each side waiting to see what the other would do as the smoldering fire and brimstone of battle was quenched by a daylong summer downpour.

Finally, Lee gave the order to begin withdrawing.

Meanwhile, Confederate forces have lost the long struggle to hold their Mississippi stronghold in Vicksburg as well.

Taken together, the two Union victories at Vicksburg and Gettysburg mark a dramatic shift in the two-year war. With the Federal Army now firmly in control of the Mississippi River, along with its vital supply lines, the Confederacy is cut in half.

And now the failure of Lee’s invasion into the Federal heartland means the rebel capital of Richmond will soon find itself under pressure of attack in the coming months.

While the fog of war remains, one thing today is clear: The brave men, blue and gray, living and dead, who struggled here have consecrated this ground. If it is the fate of the Union to live, this ground will be remembered as a place of rebirth, for a nation born again, with freedom for all.